The present invention relates generally to the dehumidification of porous materials, and in particular, mineral coated electrodes and flux material. More particularly, this invention relates to the holding and reconditioning of welding rod coatings, welding wire fluxes and coatings, and welding flux materials by maintaining appropriate moisture levels within the coating and flux material. The present invention can also be utilized for dehumidification of welding apparatus including welding torch components having an affinity to moisture.
Welding involves permanently joining sections of metallic material together by bringing those sections together and briefly heating each metallic surface to a molten state, and allowing the materials to cool. Welding is considered one of the strongest methods of joining metal because the process creates an atomic bond between the materials being welded. A widely used method of welding various metallic materials together is arc welding. Arc welding involves passing high levels of electricity through a welding rod or wire across the surface of the materials to be welded. The heat caused by the transfer of electricity between the welding rod or wire and the material to be welded causes the immediate contact area of each to melt and become welded together.
The welding rod or wire is a critical component to the arc welding process. Welding rods are composed of a metallic center electrode rod coated with various amounts of a mineral flux. Welding rods come in a variety of lengths and are composed of a variety of electrode composite structures for welding various metallic compounds. As a welding rod is brought into contact with the metallic surfaces to be welded, the inner electrode melts and provides "filler" metallic material for the weld joint. As such, the welding rod is quickly consumed or "used up" and many welding rods are needed to complete most welding projects.
Welding wire, such as flux cored wire and composite/metal cored wire, typically has a core of mineral flux or composite that is surrounded by a metallic electrode. Welding wire is formed by either the drawing method or the rolling method. One of the drawbacks of either method is the formation of a seam along the length of the wire. The seam allows moisture to be absorbed into the flux. Similar to the welding rod, welding wire is brought into contact with the metallic surfaces to be welded and the electrode melts to provide a "filler" material for the weld. Welding wire ready for use is coiled on spools that are made from metal, masonite, plastic or cardboard.
A vital element to a strong weld is a molten environment free from impurities. Impurities on the surfaces of the materials being welded or the welding rod itself can cause cracks and gas pockets in the cooled weld that significantly reduces the strength and life of the weld. Welding flux acts as a catalyst and cleaning agent to the welding process and thereby strengthens the weld joint. It does this by removing oxides from the molten metal and creating a clean atmosphere around the molten metal while the pieces are joined.
However, unacceptable moisture levels within the flux (generally greater than 0.20 percent) can introduce impurities into the weld. The heat and the electric arc from the welding process break down the water moisture into its elements, hydrogen and oxygen. These elements in or near the molten weld are diffused into the weld and cause the cracks and gas pockets which weaken the weld.
All mineral coated electrodes and flux are highly absorbent and they begin absorbing moisture once unpacked from a suppliers airtight packaging. The seam commonly produced during the manufacture of welding wire also allows for moisture to be absorbed into the flux core. Because of this, welders commonly use readily available heated ovens or similar devices to bake the moisture from welding flux and welding rods. These ovens are used to both reduce the moisture content of materials that have exceeded acceptable levels and to store these materials at acceptable moisture levels. Ovens diffuse the moisture from the flux materials by means of heating the material to temperatures ranging from 250 to 1000 degrees Fahrenheit (120 to 540 degrees Celsius) from one to several hours. This heating method, while effective, is expensive and causes the materials to be difficult to work with until cooled. A further drawback is encountered with welding wire wound on plastic spools. Due to the low heat tolerance of the plastic spool, typically less than 150 degrees Fahrenheit (65 degrees Celsius), welding wire on a plastic spool cannot be heated in an oven.
The present invention provides an easier, quicker, and more efficient way to reduce and maintain the moisture content level of coated electrodes and welding flux. It can also be utilized to remove moisture from welding torches that have an affinity to moisture. The present invention comprises an airtight chamber which creates a vacuum around the materials placed within it to more efficiently expel moisture within the flux material.